Parameters Optimization for Hole Layout of Liquid CO₂ Phase-change Fracturing Technology Based on COMSOL Numerical Simulation

In order to effectively apply the liquid CO₂ phase-change fracturing to the field of low permeability coal seam reinforcement and permeability improvement, this paper simulated and optimized the parameters of hole layout of the liquid CO₂ phase-change fracturing technology based on COMSOL, and the result is validated through the test of pre-pumping coal seam gas by cross-strata borehole in Pingdingshan No.13 Mine. The results of simulation test and field test under different hole layout and hole spacing parameters show that, with the same hole spacing, the method of “blasting one hole in every three holes” is superior to that of “blasting one hole in every two holes”. Finally, it is determined that the best hole arrangement for Pingdingshan No.13 Mine is “blasting one hole in every three holes” with a hole spacing of 6 m.